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Batteries are crucial components in a solar system. They are used to store solar energy for later use or you can run appliances and devices off them directly. To keep the batteries going, they need to be recharged. We know solar panels can do that, but can you charge batteries with electricity?
An inverter is required to charge solar batteries with electricity. The inverter is needed to convert the 120V AC power supply into 12V, 24V or 48V so the current will be compatible with the battery.
How Solar Batteries are Charged and Why It is Important
Deep cycle batteries, from the low end to powerful ones like the Ampere Time LiFePO4 100ah lithium battery can be charged with solar power or AC mains power. But you cannot just plug the battery into a wall outlet.
We need to understand how a battery works with solar panels, and then you will see why charging with electricity requires an adapter or inverter.
To charge a battery with solar power, a charge controller is connected to a solar panel first, then the battery is plugged into the controller. As the panel converts sunlight into electricity, the current goes into the battery, charging it. The controller ensures only the safe maximum voltage goes into the battery.
Solar panels produce direct current (DC), and that is what goes into the battery. Whether the battery is 12, 24 or 48 volts ,the charging process is always the same.
Do I Need an Inverter to Charge a Battery?
Solar batteries are 12, 24 or 48 volts, while AC power in US homes are 120 volts. To charge a battery of a 120V wall outlet, you need an inverter or adapter to convert the voltage into 12, 24 or 48 volts, depending on the battery.
The inverter must be large enough to handle the power that will go into the battery. if you are charging a 100ah 12V battery, that is 1200 watts (amps x volts = watts).
100 x 12 = 1200
We recommend the NDDI Direct 1500 watt inverter if you want to charge a 100ah battery on electricity. If you have a large battery, a higher capacity inverter will be needed.
Make sure the inverter is compatible with the battery voltage too. Some inverters only work with 12V or 24V systems, and others are compatible with both. Check the battery voltage and capacity first and use that as guide to what inverter size will be needed.
You will also need a charge controller to keep the battery from overloading. A 24V 60A charge controller is enough to charge a 100ah battery and work with a 1500 watt inverter.
Can You Overcharge a Solar Battery on AC Power?. Only if you do not have a charge controller and an inverter. Solar systems and even those on the grid should have these components precisely to prevent overloading and overcharging. There are many different types of charge controllers, but what they all share in common is the goal, to keep batteries from sustaining charge related damage.
How to Charge Solar Batteries with a Portable AC Charger
An AC charger is exactly what it sounds like. If you have seen a portable solar charger, that is what an AC charger looks like except it is alternate current. You just have to plug your laptop or phone into the AC charger and it does the rest.
These AC chargers work like regular wall power outlets, but currently their output is limited. You can charge phones, tablets and small laptops, but there might not be enough power for gaming laptops, let alone desktop gaming systems.
Right now these chargers will only work on small batteries. If you have a lithium ion battery that power your solar generator, a portable AC charger cannot help. You are better off charging it with solar panels or an AC wall outlet.
AC chargers cost more than USB-C, but you get greater flexibility. You can hook up any device with an AC connection and it will charge. It comes down to whether you are willing to pay the price for the added flexibility. Ann as noted, it might not be sufficient to recharge large power banks. In the future portable AC chargers will have more power, but for now it is too small for most solar batteries.
Can I Charge Power Banks on Electricity?
Power banks are portable solar chargers used to recharge mobile devices. A typical power bank has a 10000mah capacity or 10 amps. They are technically batteries too with solar components built in.
Solar power banks usually have an output for AC charging. Most of them can be charged with DC or USB as well. Because their capacity is so small compared to deep cycle batteries, charge time will only take a few minutes.
These devices are meant for people on the go so they are quick. The latest models like the Blavor Portable Charger can charge mobile phones, tablets and other devices within minutes. With multiple options you can power your devices any which way you please.
Can You Connect a Solar Charger and AC Charger to a Battery Simultaneously?
Yes, you can connect solar and electric chargers to a battery, even an inverter. Some solar panel configurations may require a diode but in others it won’t be necessary. Check your solar panel product guide to check if a diode is required. Most likely it won’t be needed because current does not move backwards in PV modules.
You can set the chargers to various voltages or to “float”. If you have a big AC charger, set it to a low voltage and half the battery capacity. The key here is to make sure the chargers and battery have “smart” technologies built in that recognizes what is going on.
But where will the power come from, solar or AC? it depend on the charger configurations, but usually if solar power is available it is used first. Do not use an old AC charger because it will waste a lot of voltage, or worse damage the solar charger.
Can You Charge Solar Light Batteries with Electrical Power?
Solar lights function like solar panels so yes, you can power its batteries with any AC charger. Charging solar lights with electricity works best with NiMH or better quality batteries. You can also work with NiCad, but it might take longer to charge. If the solar lights use old style batteries it might even reduce the total life cycle.
The important thing to remember for solar lights – and solar batteries – is the voltage. No matter which power supply you decide to use to charge the battery, its voltage must be compatible. Keep an eye on the temperature, because if it gets too hot it is a sign of overcharging or the battery does not accept the power supply.
Solar Charge vs. Electric Battery Charge – Which is Best for Solar Batteries?
Back in the day it was easy to say that electric charging was better. It was faster, more reliable and readily available. However, solar chargers have improved significantly over the years. The best portable solar chargers have support for USB QuickCharge and USB-C, allowing you to charge even faster.
One drawback with electrical charging is lack of mobility. Without access to an electrical outlet you can’t charge the battery. Portable AC chargers are suitable for small power banks but that’s it. On the other hand, solar panels won’t run without the sun unless it has a power bank built in.
In other words, both methods have benefits and drawbacks. In some cases it is better to go with electrical charging, but in others you would do better with solar. Most solar power users go with both. They charge a battery at home by a wall outlet and use a solar generator or another solar device to recharge it on the road. There is no reason to pick one when you can have both.
Solar power has its benefits, but there are times when your only choice is to go electric. The good thing is you are no longer just limited to an AC wall outlet as there are many chargers at your disposal. And with solar batteries becoming more versatile, you never have to deal with lower power.
I am an advocate of solar power. Through portablesolarexpert.com I want to share with all of you what I have learned and cotinue to learn about renewable energy.